Code Playground

@charset "UTF-8";
@import url(https://fonts.googleapis.com/css?family=Nunito+Sans:300,400,600,700,800);
*,
:after,
:before {
  box-sizing: border-box;
  padding: 0;
  margin: 0;
}
@property --val {
  syntax: '<integer>';
  inherits: true;
  initial-value: 0; 
}

label {
  --c: #547980; /* slider color */
  --g: round(.3em,1px);  /* the gap */
  --l: round(.2em,1px);  /* line thickness*/
  --s: round(1.3em,1px); /* thumb size*/
  --t: round(.8em,1px);  /* tooltip tail size */
  --r: round(.8em,1px);  /* tooltip radius */
  
  timeline-scope: --thumb-view;
  translate: 0; /* No, It's not useless so don't remove it (or remove it and see what happens) */ 
  font-size: 24px;
}

input {
  width: 400px;
  height: var(--s); /* needed for Firefox*/
  --_c: color-mix(in srgb, var(--c), #000 var(--p,0%));
  appearance :none;
  background: none;
  cursor: pointer;
  overflow: hidden;
  font-size: inherit;
}
input:focus-visible,
input:hover{
  --p: 25%;
}
input:active,
input:focus-visible{
  --_b: var(--s)
}
/* chromium */
input[type="range" i]::-webkit-slider-thumb{
  height: var(--s);
  aspect-ratio: 1;
  border-radius: 50%;
  box-shadow: 0 0 0 var(--_b,var(--l)) inset var(--_c);
  border-image: linear-gradient(90deg,var(--_c) 50%,#ababab 0) 0 1/calc(50% - var(--l)/2) 100vw/0 calc(100vw + var(--g));
  -webkit-appearance: none;
  appearance: none;
  transition: .3s;
  anchor-name: --thumb;
  view-timeline: --thumb-view inline;
  view-timeline-inset: var(--s);
}
/* Firefox */
input[type="range"]::-moz-range-thumb {
  height: var(--s);
  width: var(--s);
  background: none;
  border-radius: 50%;
  box-shadow: 0 0 0 var(--_b,var(--l)) inset var(--_c);
  border-image: linear-gradient(90deg,var(--_c) 50%,#ababab 0) 0 1/calc(50% - var(--l)/2) 100vw/0 calc(100vw + var(--g));
  -moz-appearance: none;
  appearance: none;
  transition: .3s;
  anchor-name: --thumb;
  view-timeline: --thumb-view inline;
  view-timeline-inset: var(--s);
}
output {
  position-anchor: --thumb;
  position: absolute;
  inset-area: top span-all;
  color: #fff;
  font-weight: bold;
  font-family: sans-serif;
  text-align: center;
  padding-block: .5em;
  width: 4em;
  background: #CC333F;
  --val:var(--min);
  border-bottom: var(--t) solid #0000;
  border-radius: var(--r)/var(--r) var(--r) calc(var(--r) + var(--t)) calc(var(--r) + var(--t));
  --_m: 100%/var(--t) var(--t) no-repeat;
  --_g: 100%,#0000 99%,#000 102%;
  mask:
    linear-gradient(#000 0 0) padding-box,
    radial-gradient(100% 100% at 100% var(--_g)) calc(50% + var(--t)/2) var(--_m),
    radial-gradient(100% 100% at 0    var(--_g)) calc(50% - var(--t)/2) var(--_m);
  animation: range linear;
  animation-timeline: --thumb-view;
}
output.bottom {
  inset-area: bottom span-all;
  border-top: var(--t) solid #0000;
  border-bottom: none;
  border-radius: var(--r)/calc(var(--r) + var(--t)) calc(var(--r) + var(--t)) var(--r) var(--r);
  --_m: 0%/var(--t) var(--t) no-repeat;
  --_g: 0%,#0000 99%,#000 102%;
}
output:before {
  content: counter(num);
  counter-reset: num var(--val);
}

@keyframes range {
  0% {background: #8A9B0F;--val:var(--max)}
}

@supports not (anchor-name: ---) {
  output {
    display: none;
  }
}

/**/
body {
  margin: 0;
  min-height: 100vh;
  display: grid;
  gap: 20px;
  place-content: center;
  background: repeating-linear-gradient(-45deg, #fff 0 20px, #f9f9f9 0 40px);
}

Frontend Forever App